Change of estate planning?

I am in my early 50's; my sister is in her early 40's. She is divorced w/ 2 children; I am divorced w no children.

My sister is notoriously bad w/ money. In college she overdrew her bank account by thousands. I recently learned that prior to her marriage she had to declare bankruptcy due to her spending. Her divorce left her with debt.

In all 3 cases, my parents bailed her out. They re-funded her checking account, paid all the expenses associated with her bankruptcy, and took a home equity loan so she could pay off her divorce debt.

I, too, was saddled w/ significant debt from my divorce and lived like a monk for 3 years to pay it all off. I have lost jobs, put myself through school and faced financial hardship never thinking to ask my parents for money.

Many years ago my parents told me that they know my sister is financially reckless. Because of that, they told me that they planned to transfer title of their home to me when it was time for them to give it up and go to assisted living. My sister would be receiving money but a significantly less amount. This, due to their financial assistance over the years.

This seemed fair to me. Now my parents tell me my sister and I will split the estate. My parents are now applying pressure to set up trusts for my nephews.

My parents can do what they want w/ their estate, it's their $. I am objecting to being told to set up trusts for my nephews. How can I handle this?